Classifying apparatus, classifying method, and method for producing toner

Abstract

A classifying apparatus including: a rotor with a plurality of annularly disposed blades, which rotates; and a louver with a plurality of blades which are disposed at an outer circumferential portion of the rotor so as to supply from the outer circumferential portion a fluid for dispersing and classifying a powder material, wherein the powder material is supplied to a gap between the rotor and the louver and centrifugally classified into fine powder and coarse powder, and wherein at least one of the following relationships is satisfied: Relationship (1): α≧50° Relationship (2): D 2 /D 1 ≧1.17 where α denotes an angle formed between imaginary lines connecting the center of the rotor with both ends of each blade of the louver, D 1 denotes a diameter of the rotor, and D 2 denotes an inner diameter of the louver.

The invention claimed is: 
     
       1. A classifying apparatus, comprising:
 a rotor comprising a plurality of annularly disposed blades, which rotates; and 
 a louver comprising a plurality of blades which are disposed at an outer circumferential portion of the rotor so as to supply from an outer circumferential portion a fluid for dispersing and classifying a powder material, 
 wherein 
 the powder material is supplied to a gap between the rotor and the louver and is centrifugally classified into a fine powder and a coarse powder, and 
 wherein both of the following relationships is satisfied:
   α≧50°  Relationship (1):
 
   1.17 ≦D 2 /D 1≦1.20  Relationship (2):
 
 
 wherein 
 α denotes an angle formed between imaginary lines connecting the center of the rotor with both ends of each blade of the louver, 
 D 1  denotes a diameter of the rotor, and 
 D 2  denotes an inner diameter of the louver, and 
 wherein the angle formed between imaginary lines connecting the center of the rotor with the respective ends of a three-layer overlapping portion of a first blade of said louver and two blades of said louver adjacent to said first blade is equal to or more than 5° and equal to or less than 15°. 
 
     
     
       2. The apparatus of  claim 1 , wherein the blades of the louver are provided at regular intervals on a concentric circle, with a central shaft of the rotor situated at the center. 
     
     
       3. The apparatus of  claim 1 , further comprising a regenerative converter, wherein a number of rotations of the rotor is controlled by the regenerative converter such that the number becomes a predetermined number of rotations. 
     
     
       4. A method for classifying a powder material, comprising:
 providing a classifying apparatus as claimed in  claim 1 ; 
 supplying the powder material; 
 leading supplied powder material to the outer circumferential portion of the rotor; 
 supplying, by use of the louver from the outer circumferential portion, the fluid for dispersing and classifying the powder material; and 
 centrifugally classifying the powder material supplied to the gap between the rotor and the louver into the fine powder and the coarse powder. 
 
     
     
       5. A method for producing a toner, by classifying a powder material, comprising:
 providing a classifying apparatus as claimed in  claim 1 ; 
 supplying the powder material; 
 leading supplied powder material to the outer circumferential portion of the rotor; 
 supplying, by use of the louver from the outer circumferential portion, the fluid for dispersing and classifying the powder material; and 
 centrifugally classifying the powder material supplied to the gap between the rotor and the louver into the fine powder and the coarse powder. 
 
     
     
       6. The apparatus of  claim 2 , further comprising a regenerative converter, wherein a number of rotations of the rotor is controlled by the regenerative converter such that the number becomes a predetermined number of rotations. 
     
     
       7. A method for classifying a powder material, comprising:
 providing a classifying apparatus as claimed in  claim 2 ; 
 supplying the powder material; 
 leading supplied powder material to the outer circumferential portion of the rotor; 
 supplying, by use of the louver from the outer circumferential portion, the fluid for dispersing and classifying the powder material; and 
 centrifugally classifying the powder material supplied to the gap between the rotor and the louver into the fine powder and the coarse powder. 
 
     
     
       8. A method for classifying a powder material, comprising:
 providing a classifying apparatus as claimed in  claim 3 ; 
 supplying the powder material; 
 leading supplied powder material to the outer circumferential portion of the rotor; 
 supplying, by use of the louver from the outer circumferential portion, the fluid for dispersing and classifying the powder material; and 
 centrifugally classifying the powder material supplied to the gap between the rotor and the louver into the fine powder and the coarse powder. 
 
     
     
       9. A method for producing a toner, by classifying a powder material, comprising:
 providing a classifying apparatus as claimed in  claim 2 ; 
 supplying the powder material; 
 leading supplied powder material to the outer circumferential portion of the rotor; 
 supplying, by use of the louver from the outer circumferential portion, the fluid for dispersing and classifying the powder material; and 
 centrifugally classifying the powder material supplied to the gap between the rotor and the louver into the fine powder and the coarse powder. 
 
     
     
       10. A method for producing a toner, by classifying a powder material, comprising:
 providing a classifying apparatus as claimed in  claim 3 ; 
 supplying the powder material; 
 leading supplied powder material to the outer circumferential portion of the rotor; 
 supplying, by use of the louver from the outer circumferential portion, the fluid for dispersing and classifying the powder material; and 
 centrifugally classifying the powder material supplied to the gap between the rotor and the louver into the fine powder and the coarse powder. 
 
     
     
       11. The apparatus of  claim 1 , wherein for Relationship (2), 1.17<D 2 /D 1 <1.19.